Ingot and method of manufacture

ABSTRACT

A gold ingot comprising: a generally obround body having, a rounded spherical surface on each opposing end of said obround body, four curvilinear longitudinal edges along a main axis of said obround body, four flat longitudinal surfaces along the main axis of said obround body, and a circular void that extends through two opposing surfaces of said four flat longitudinal surfaces, said circular void located between centers of radii located on the flat longitudinal surfaces adjacent the rounded spherical surface on each opposing end of said obround body.

FIELD OF THE INVENTION

The present invention relates to metal ingots, and more particularly togold ingots and a method of manufacturing same into a novel shapeappropriate to be worn as jewellery.

BACKGROUND OF THE INVENTION

An ingot is a mass of metal (often tin, steel, gold, or silver) that hasbeen cast into a bar, block, mold, sheet, plate, or the like, of acertain size and shape that is convenient for storage and transportpurposes, or for working into another semi-finished or finished product.In this respect, ingots are typically rectangular in shape, which allowsfor stacking.

The problem with the typical rectangular shape, however, is thatalthough it may be convenient for storage and transport by commercialmeans, it is not convenient to be worn as jewelry by individuals in thenormal course.

The present invention seeks to overcome problems associated with goldjewelry in the traditional shape and size, by providing an ingot thatallows for ease of personal transport and wearability.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a gold ingot comprising: agenerally obround body having, a rounded spherical surface on eachopposing end of said obround body, four curvilinear longitudinal edgesalong a main axis of said obround body, four flat longitudinal surfacesalong the main axis of said obround body, and a circular void thatextends through two opposing surfaces of said four flat longitudinalsurfaces, said circular void located between centers of radii located onthe flat longitudinal surfaces adjacent the rounded spherical surface oneach opposing end of said obround body.

In another aspect, the present invention provides a gold ingotcomprising: a generally obround body having, a rounded spherical surfaceon each opposing end of said obround body, four curvilinear longitudinaledges along a main axis of said obround body, four flat longitudinalsurfaces along the main axis of said obround body, and a circular voidthat extends through two opposing surfaces of said four curvilinearlongitudinal surfaces, said circular void located between centers ofradii located on the curvilinear longitudinal surfaces adjacent therounded spherical surface on each opposing end of said obround body.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with referenceto the accompanying drawings in which:

FIG. 1 is a perspective view of one embodiment of an INGOT in accordancewith the present invention;

FIG. 2 a is a front elevational view of the embodiment shown in FIG. 1 ,the rear elevational view being identical;

FIG. 2 b is a representation of the INGOT shown in FIG. 2 a , withexample measurements that would assist in forming a one-Troy-ounceingot;

FIG. 3 a is a left side elevational view of the embodiment shown in FIG.1 , the right side elevational view being identical;

FIG. 3 b is a representation of the INGOT shown in FIG. 3 a , withexample measurements that would assist in forming a one-Troy-ounceingot;

FIG. 4 a is a top plan view of the embodiment shown in FIG. 1 , thebottom plan view being identical;

FIG. 4 b is a representation of the INGOT shown in FIG. 4 a , withexample measurements that would assist in forming a one-Troy-ounceingot; and

FIG. 5 is a schematic representation of a hot chamber machine used in anexemplary method to produce an ingot of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1 , the present invention involves themanufacture of a one-Troy-ounce gold bullion bar/ingot 100 having anovel shape and features that makes it more akin to jewellery than abullion bar made primarily for commercial storage. However, unlikejewellery, which is normally alloyed, the ingot 100 of the presentinvention consists of 24 k gold (99.99% pure and unalloyed); and, unlikea coin or bullion bar, which are the only forms of unalloyed goldnormally available, the ingot 100 of the present invention can becarried on a chain or cord around an individual's neck or wrist for easeof transport.

Moreover, with particular reference to FIGS. 1, 2 a, 3 a, and 4 a, theingot 100 of the present invention is generally obround and shaped to:

-   -   a. minimize wear and prevent irritation, if worn, by having        smooth surfaces, namely rounded spherical ends 110 and        curvilinear longitudinal edges 120, with no sharp or pointed        corners or edges;    -   b. prevent rolling (and therefore potential loss) if dropped, by        having flat longitudinal surfaces 130 on 4 sides; and    -   c. accommodate markings on its flat longitudinal surfaces 130 to        indicate assayer/producer, weight, fineness, and serial number,        as desired.

With reference to FIGS. 1, 2 a, and 2 b, wearability is facilitated by ahole or void 140 about 2 mm in diameter, through which a chain, cord, orthe like can pass to allow the ingot 100 to be worn around anindividual's neck or wrist. Depending on customer preference, this holeor void 140 may be located at any point along the main axis of the ingot100, preferably on a flat longitudinal surface 130 thereof between thecenters of radii 150 adjacent the rounded spherical ends 110. Fordepiction purposes, the hole or void 140 is shown in the Figurescentered on the ingot 100 between the centers of radii 150.

Various exemplary measurements are provided in FIGS. 2 b, 3 b, and 4 bthat enable the creation of a one-Troy-ounce gold ingot 100 of thepresent invention. However, a person skilled in the art would be able toproduce an ingot 100 of different size/weight as desired.

A person skilled in the art would appreciate that various known methodscould potentially be used to form an ingot 100 of the present invention.For instance, the skilled person could consider use of a traditionalcasting method, a vacuum casting method, direct fusion, or a hot chamberdie casting method, among other methods.

An exemplary method of manufacturing an ingot 100 of the presentinvention involves the use of a modified hot chamber die casting methodas described hereinafter.

In order to manufacture the ingot 100, a 3-dimensional definition iscreated using CAD (Computer-Aided-Design) software, and a steelwax-molding die is created from the CAD definition.

From this a “positive” replica of the ingot is molded in wax or polymerusing the wax-molding die. A hole is drilled into the injection-moldedwax “positive” to accommodate a core, and a core is inserted into thewax “positive” to form the necessary hole/void in the ingot.

A “negative” of the ingot is then formed around the “positive” waximpression. This “negative” is created using an appropriate sand typeand molding resin in a forming box or flask. The “negative” sand mold ishardened through chemical or heat processes.

Two holes are subsequently drilled in the top surface of the hardenedsand mold. These holes fully penetrate the upper mold wall and mayextend into the wax somewhat. Molten gold is injected into the hardenedsand mold through one hole; the other hole is a vent.

Gold injection is achieved via piston to inject the exact mass required.With reference to FIG. 5 , a pot 200 holds molten gold heated by aburner 210. Within the molten gold pool is a gooseneck 220. Thegooseneck is a device to accurately draw in molten metal and tosubsequently press out through a nozzle 230 a fixed quantity of moltenmetal. It includes a power cylinder 240, a plunger 250, a plungercylinder 260 and an intake port 270.

Upon retraction of the plunger 250 upwards, a vacuum is created withinthe plunger cylinder 260, and molten metal from the pot 200 is drawninto the plunger cylinder 260. Next, the power cylinder 240 pushes theplunger 250 downward. This blocks the intake port 270 to prevent moltenmetal from returning to the pot 200. Molten metal is instead forcedthrough the gooseneck 220 to the nozzle 230. The nozzle 230 is alignedwith a sand mold (not shown) so as to accept a 1-Troy-Ounce quantity ofmolten metal. Upon subsequent cooling, the sand mold is broken away fromthe molded ingot and discarded.

The core is then removed from the molded ingot, and sprues from the pourhole and vent hole are trimmed. The injection (sprue) surface issmoothed mechanically, any desired/necessary marks are stamped on thefour flat longitudinal surfaces 130 of the ingot, and the ingot ispolished.

This method is novel in that the molding of the finished ingot is acombination of two methods: 1) the traditional lost-wax method ofmolding; and 2) the high-pressure die-casting method. Since the melt isinjected directly into the sand mold, with direct venting from the sandmold, the melt injection in this case does not require high pressure—itis an atmospheric-pressure process. However, the method utilizesmechanical injection at low pressure in order to: 1) accurately meterthe quantity of melt injected; 2) speed the melt flow into the mold; and3) ensure the mold cavity is completely filled. An excess quantity ofmelt is injected to ensure complete fill of the mold cavity. The excessis removed afterward.

We claim:
 1. A gold ingot comprising: a generally obround body having, arounded spherical surface on each opposing end of said obround body,four curvilinear longitudinal edges along a main axis of said obroundbody, four flat longitudinal surfaces along the main axis of saidobround body, and circular void that extends through two opposingsurfaces of said four flat longitudinal surfaces, said circular voidlocated between centers of radii located on the flat longitudinalsurfaces adjacent the rounded spherical surface on each opposing end ofsaid obround body.
 2. The gold ingot of claim 1, wherein the gold ingotis a one-Troy-ounce ingot.
 3. A gold ingot comprising: a generallyobround body having, a rounded spherical surface on each opposing end ofsaid obround body, four curvilinear longitudinal edges along a main axisof said obround body, four flat longitudinal surfaces along the mainaxis of said obround body, and a circular void that extends through twoopposing surfaces of said four curvilinear longitudinal surfaces, saidcircular void located between centers of radii located on thecurvilinear longitudinal surfaces adjacent the rounded spherical surfaceon each opposing end of said obround body.
 4. The gold ingot of claim 3,wherein the gold ingot is a one-Troy-ounce ingot.
 5. An ingotcomprising: a generally obround body having, a rounded spherical surfaceon each opposing end of said obround body, four curvilinear longitudinaledges along a main axis of said obround body, four flat longitudinalsurfaces along the main axis of said obround body, and a circular voidthat extends through two opposing surfaces of said four curvilinearlongitudinal surfaces, said circular void located between centers ofradii located on the curvilinear longitudinal surfaces adjacent therounded spherical surface on each opposing end of said obround body. 6.The gold ingot of claim 5, wherein the ingot is a one-Troy-ounce ingot.7. The ingot of claim 6, wherein the ingot is formed from a preciousmetal.
 8. The ingot of claim 7, wherein the precious metal is gold. 9.The ingot of claim 7, wherein the precious metal is silver.